饲用型小黑麦遗传图谱构建及草产量相关性状QTLs初步定位

本研究以饲用型小黑麦杂交F₂代为作图群体，利用ISSR分子标记构建了遗传连锁图谱，并对小黑麦草产量相关性状（株高，分蘖数，单株生物量）进行了QTLs定位，可为小黑麦草产量相关主效QTL挖掘、功能基因定位以及分子标记辅助育种奠定基础。结果表明：521个F₂代单株草产量相关性状的田间表型数据呈连续变异，分布频率大致接近正态分布，可用于QTLs定位。该遗传图谱包含7个连锁群，图谱总长度为542.9 cM，标记间平均距离为5.90 cM，共有92个位点。对草产量相关性状基因进行QTL定位分析，共检测到17个QTLs，分布在6个连锁群上，控制株高的QTLs有5个，贡献率为6.7%~13.2%；控制分蘖数的QTLs有7个，贡献率为5.4%~15.4%；控制单株生物量的QTLs有5个，贡献率为7.4%~12.4%。其中QPH7-2，QNT2-2和QBS2分别对小黑麦株高、分蘖数和单株生物量的贡献率最大，为主效QTLs，可对其进行进一步克隆、转化及利用。

Constructions on the Linkage Genetic Map and Initial Locations on QTLs Related to the Hay Yield of Forage Triticale

In this study,F₂ generation derived from forage triticale hybrids were used as the mapping population,The genetic linkage map was constructed by using ISSR molecular marker and QTLs were mapped to yield-related traits (plant height,number of tillers,above ground biomass of single plant) of triticale. It could lay a foundation for main QTL mining,functional gene mapping and molecular marker-assisted breeding of triticale. The results showed that the field phenotypic data of 521 F₂ generation grass yield-related traits showed continuous variation,and the distribution frequency was close to normal distribution,which could be used for QTLs localization. The linkage map included 7 linkage groups,the total length of map was 542.9 cM,the averaged distance among markers was 5.90 cM,and there were 92 loci. QTL results showed that there were 17 QTLs related to the hay yield in triticale. These QTLs distributed on 6 linkage groups. There were 5 QTLs controlling the plant height,which contribution rate varied from 6.7% to 13.2%. There were 7 QTLs controlling the number of tillers,which contribution rate changed from 5.4% to 15.4%. There were 5 QTLs controlling the aboveground biomass of the single plant,which contribution rate varied from 7.4% to 12.4%. Among them,QPH7-2,QNT2-2 and QBS2 have the highest contribution rate to plant height,number of tillers and aboveground biomass of single plant,respectively,so they were the main QTLs,which could be further cloned,transformed and utilized.